KR100344336B1 - Sub-frame structure of vehicle - Google Patents

Abstract

The present invention provides a subframe structure of a vehicle which suppresses deformation of the inclined portion formed on the upper end side of the spring accommodating portion, maintains the alignment state of the wheel appropriately, secures steering stability, and prevents durability degradation.

A pair of left and right spring receptacles 101 which are fixed to the left and right side members 4 extending in the front-rear direction X of the vehicle and receive the road surface reaction force F from the rear wheel W via the coil spring 31. ), A pair of left and right inclined portions 102 extending from both spring receiving portions 101 toward the lower side of the vehicle body side, and lower (lower) arms 11 connected to the lower ends of both inclined portions 102 are connected to each other. A vehicle width direction extending member 1A having a pair of left and right bent portions 103, a linear center portion 104 extending from both bends toward the center of the vehicle body, and a vertical plate portion to which the rear end of the differential device 16 of the vehicle is attached. A reinforcing plate member 8 having a 801, and an edge portion of the reinforcing plate member 8 is bonded and fixed to both the inclined portions 102 and the straight center portion 104 of the vehicle width direction extending member 1A, respectively. It is.

Description

Sub-frame structure of vehicle

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subframe structure of a vehicle, and more particularly, to a subframe structure of a vehicle that is joined to and fixed to a lower wall component member of a vehicle body and supports a part of a suspension device or a driving force transmission system.

For example, a vehicle attaches wheels to each side of the vehicle front, rear, left, and right through a suspension device, and transmits rotational force to each of these wheels via a driving force transmission system disposed under the vehicle body. Thus, a suspension device, a driving force transmission system, etc. are provided below the vehicle body, and these are the floor member which is a lower wall structural member of a vehicle body, and a pair of left and right side members welded to this floor member and extended in the front-back direction of a vehicle body, respectively, The side members are joined to each other, and are coupled to each other through a variety of brackets or subframes, such as a straight cross member welded to the floor member. For this reason, it is necessary for the lower wall constituent member of the vehicle body to support the suspension device, the driving force transmission system, the wheels, and the like with durability and precision, and to maintain sufficient strength.

By the way, as a sub-frame which couples the left and right ends to a pair of left and right side members installed in the lower part of the vehicle body, in particular, between the left and right end coupling portions between the left and right inclined portions and the lower ends of these left and right inclined portions in a downwardly projecting shape as a straight center portion. It is known to form continuously.

The sub-frame structure is offset between the left and right coupling portions and the lower bends of the left and right inclined portions by a predetermined amount up and down, and furthermore, each of the bends has a gum bush that is the base of the lower (lower) arm, which is a left and right suspension arm. The pin is connected via. Here, a coil spring is mounted between the spring receiving portion and the central portion of the lock arm. In this case, each swing end of the left and right lock arms supports the wheels via a knuckle, and the road reaction force from the wheels is input to the left and right spring receiving portions via the lower arm and the coil spring, and left and right from these spring receiving portions. It is distributed and supported on the side member side.

An example of such a subframe structure is disclosed in Japanese Patent Laid-Open No. 7-315245. Here, among the front and rear pairs of cross members for welding the left and right ends to a pair of left and right side members, the front cross member is formed in the upward protrusion shape, and the rear cross member is formed in the downward protrusion shape, respectively. Even when elastically deforms toward the center of the vehicle body, the displacement amounts of the front and rear cross members at that time are equal to each other so that the deviation of the toe angle of the wheel does not occur. The cross member of the back used here protrudes the longitudinal bracket in the area | region secured in the center direction, and attaches a differential housing to this longitudinal bracket.

However, in the sub-frame structure in which the spring receiving portion and the bent portion are offset upward and downward as described above, when the spring receiving portions at the upper left and right pairs of the inclined portions receive a large input load, the spring receiving portions at the upper ends of the inclined portions together with the respective side members. There is a problem in that each of the bent portions is deformed toward the center portion of the vehicle body, causing misalignment of the wheel alignment state and lowering the durability of the cross member itself. In particular, in the off-road vehicle, the vertical stroke of the wheel is set large so that the coil spring is long, the amount of offset in the vertical direction of the spring accommodating portion and the bent portion increases, and the inclined portion deforms toward the center of the vehicle body with the curved side as the point. It tends to be large and causes a problem of causing a large shift in the alignment state of the wheels.

In addition, in the subframe structure of the vehicle disclosed in Japanese Patent Laid-Open No. 7-315245, the displacement of the front and rear cross members is allowed, and when only one of the front and rear cross members is used, the cross member and the side member elastically move toward the center of the vehicle body together. It is easy to deform | transform, and it is easy to produce the shift | offset | difference in the alignment state of a wheel. In this case, the lower edge of the longitudinal bracket with the differential housing is welded to the center of the cross member. However, if the spring receiving portion is formed in the cross member here, in this case, when the road reaction force is applied to the spring receiving portion, the cross member is It is easy to deform | transform to the vehicle body center side by making the junction end of the longitudinal bracket into a point, and it has the disadvantage that it causes a shift in the alignment state of a wheel, and causes durability fall.

An object of the present invention is to suppress the deformation of the inclined portion of the inclined portion formed on the upper end of the spring body to maintain the alignment state of the wheel appropriately, to ensure the stability of adjustment, and to prevent the durability of the vehicle subframe structure To provide.

1 is a plan view of the main portion of the lower vehicle body having a subframe structure of a vehicle as an embodiment of the present invention.

FIG. 2 is a cutaway rear view of the main part of the lower body having the subframe structure of the vehicle of FIG. 1; FIG.

3 is a perspective view of the chassis member used in the lower body having the subframe structure of the vehicle of FIG.

4A is an enlarged sectional view taken along the line A-A of FIG. 1 showing a main part of a lower vehicle body having a subframe structure of the vehicle of FIG.

4B is an enlarged cross-sectional view taken along the line B-B of FIG. 1 showing a main part of a lower vehicle body having a subframe structure of the vehicle of FIG.

5 is an explanatory diagram of deformation due to an input load of a lower vehicle body having a subframe structure of the vehicle of FIG.

* Description of the symbols for the main parts of the drawings *

1: bend cross member 1A: vehicle width direction extension member

4 side member 7 front and rear extending member

8: reinforcement plate 11: lower arm

16: differential housing 31: coil spring

101: spring receiving portion 102: inclined portion

103: bend portion 104: straight center portion

F: Input load (road reaction force) Ms: Chassis member (subframe)

S: Rear suspension device X: Front-rear direction

Y: vehicle width direction W: rear wheel

In order to achieve the above object, in the invention of claim 1, the vehicle width direction extension member is provided, and the vehicle width direction extension member is joined to and fixed to a pair of left and right side members extending in the front and rear direction of the vehicle, and the road surface reaction force from the wheel is fixed. A pair of left and right pairs of spring accommodating portions receiving a coil through a coil spring, a pair of left and right inclined portions extending downward from both spring accommodating portions toward the center side of the vehicle body, and formed at a lower end of the two inclined portions and connected with a suspension arm; And a reinforcing plate member having a pair of right and left bent portions, a vehicle width direction extending member having a straight center portion extending from both bend portions to a vehicle body center side, and a vertical plate portion to which a rear end of the differential device of the vehicle is attached. An edge portion includes the both inclined portions and the straight center of the vehicle widthwise extending member. It is respectively fixed to the joint.

Here, the end edges of the reinforcing plate are joined and fixed to both the inclined portions and the straight central portion formed with the spring receiving portion at the upper end side, and the both inclined portions formed with the spring receiving portion at the upper side deform to the center of the vehicle body with each bent portion side as a point. Even if it does so, the reinforcement board material here functions as a support member, and the displacement which the two inclination parts which formed the spring accommodating part in the upper end approaching each other can reliably be prevented. For this reason, the deformation | transformation to the vehicle body center side of both inclination parts which deform | transformed the spring accommodating part to the upper end side can be suppressed, the alignment state of a wheel can be maintained appropriately, a steering stability can be ensured, and durability fall can be prevented, The differential device can be reliably supported so that the parts can be shared. In addition, since the rigidity of the cross member is strengthened by the reinforcing plate, generation of rod noise due to resonance of the cross member can be reduced.

Preferably, the pair of left and right spring receptacles may be fastened to the pair of left and right side members. In this case, a suspension device or a part of the power transmission mechanism can be assembled and subassembly to the cross member, and the subassembly cross member assembly can be attached to the vehicle body, and workability at the time of design can be improved. .

In the invention of claim 2, in the subframe structure of the vehicle according to claim 1, the left and right pair of spring receiving portions are fastened and coupled to the left and right pair of side members, and one end is joined and fixed to the vehicle body center side from each spring receiving portion. Has a pair of front and rear extension members fastened to each side member or a cross member which mutually couples each side member, and the left and right edges of the reinforcing plate are joined and fixed to one end of the front and rear extension members.

Here, the one end of the forward and backward extension member is fixed to both spring receiving portions, and the one end of the reinforcing plate is bonded and fixed to one end of the forward and backward extension member so that the reinforcing plate approaches each other as the supporting member. It is possible to prevent the displacement, and therefore, to maintain the proper alignment of the wheel, to ensure the steering stability to prevent durability degradation, in particular the front and rear extension member can strengthen the rigidity of the entire sub-frame, Also in this respect, the shift | offset | difference in a wheel alignment state can be prevented reliably.

1 and 2 illustrate a lower body structure of an automobile including a subframe structure of a vehicle to which the present invention is applied.

The lower body structure forms attachment portions J1 and J2 on the lower wall constituent members described later, and fastens and fixes the chassis member Ms as a subframe to the attachment portion, and the lower body structure includes the chassis member Ms and A part of the driving force transmission system PT which transmits a driving force to the rear suspension apparatus S and the rear wheel W which attach the rear wheel W in the appropriate alignment state with respect to the other lower wall structural member is attached.

As shown in FIG. 2, the lower wall member is joined to the floor material 3 facing the vehicle compartment CR and the bottom surface of the floor material 3 as shown in FIG. 2, and as shown in FIG. X) consists of a pair of long left and right side members 4 and the cross members 5 welded to the floor material 3 while integrally coupling the two side members. The cross member 5 is welded to the relatively front side (upper side in FIG. 1) of the pair of left and right side members 4, and the all-right and left and right mounting portions (from the left and right ends of the cross member 5 to the vehicle body center side in a predetermined amount). J1) is formed. Moreover, the rear attachment parts J2 of the rear left and right sides are formed in the comparatively rear side (lower side in FIG. 1) of the pair of left and right side members 4, respectively.

Each attachment part J1, J2 is equipped with the bolt hole not shown which inserts the fastening bolt which is not shown in the up-down direction, and is attached to the lower surface of each attachment part J1, J2 by the bolt inserted in the bolt hole. The opposing parts on the side of the chassis member Ms to be contacted are fastened and engaged.

As shown in FIG. 3, the chassis member Ms constituting the main part of the subframe structure of the vehicle to which the present invention is applied is provided to the bent cross member 1 and the bent cross member 1 which are extended in the vehicle width direction Y. It consists of a pair of left and right front-back direction extension members 7 extended in the front-back direction X which welded the rear end.

As shown in FIG. 2, the bend cross member 1 includes a vehicle width direction extending member 1A and a reinforcing plate member 8 having end edges joined to and fixed to the vehicle width direction extending member. Here, the vehicle-width direction extending member 1A is a pair of left and right pairs of spring-receiving portions 101 which are joined to and fixed to both side members 4, and downward from the respective spring-receiving portions 101 toward the vehicle body center side, respectively. A pair of left and right inclined portions 102, a pair of left and right bent portions 103 formed at the lower ends of both inclined portions, and a straight center portion 104 extending from both bent portions 103 to the vehicle body center side; The reinforcement board 8 is welded on it.

As shown in Fig. 4A, the vehicle widthwise direction extending member 1A welds the outer circumferential portion by overlapping the upper plate member 1a of the hat-shaped cross section and the lower plate member 1b of the flat plate shape with each other, and closes the cross-sectional shape. It is formed to achieve. Moreover, the spring accommodating part 101 of the vehicle width direction extension member 1A forms the both ends of the upper board material 1a and the lower board material 1b as a dish-shaped end part, and overlaps them up and down, and has a dish-shaped spring accommodating part ( 101). The central portion of the spring receiving portion 101 forms a bolt hole h, and the same portion overlaps with the rear attachment portions J2 of the left and right side members 4, and is fastened and fixed with a fastening bolt (not shown). . The left and right pair of bent portions 103 form downward recesses not shown in the lower end of the closed end portion formed by the upper plate member 1a and the lower plate member 1b, and the lower arm 11 described later as a suspension arm in this recess portion. The base of the) is fitted to connect the base.

The reinforcing plate 8 is a sheet metal member which extends in the vehicle width direction Y, and is formed with the longitudinal plate part 801 and the full extension part 802 which extends and bends forward from the upper edge. The left and right edges of the end plate portion 801 are welded to the rear ends of the front and rear extending members 7, and the lower edges are continuously welded over the left and right pairs of inclined portions 102, the bent portions 103, and the straight center portion 104. do. In addition, the left and right edges of the front extension part 802 are welded to the vehicle body side wall near the rear end of the front-rear extension member 7, thereby reinforcing the rigidity of the reinforcing plate 8 itself. In addition, the rear end of the front-rear extension member 7 is welded to the vehicle body center side wall of the left and right vehicle outer side walls on the reinforcement plate 8 to the vehicle body center side wall of the left and right spring accommodating parts 101, and consequently the left and right spring accommodating parts. Reference numeral 101 is a state where the joint is fixed to the left and right edges of the end plate portion 801 via the front and rear extending member 7.

The end plate portion 801 forms a pair of left and right differential attachment holes 12 (refer to FIG. 3) at a central portion thereof at predetermined intervals in the vehicle width direction Y. As shown in FIG. 4A, the differential attachment hole 12 supports the outer cylinder 13 by press fitting, and the outer cylinder 13 heat-joins the gum bush 15 supporting the inner cylinder 14. In front of the inner cylinder 14, the differential housing 16 of the drive force transmission system PT is provided opposite. The rear end of the differential housing 16 is provided with a boss 161 protruding from the rear wall of the differential housing 16, and the bolt 17 having inserted the inner cylinder 14 into the screw hole formed therein is screwed into the rear end of the differential housing 16. It is attached to this end plate part 801.

The pair of left and right front and rear extension members 7 extending in the front and rear directions X and being installed in parallel with each other is welded to the side wall of the vehicle body center side of the spring receiving portion 101 of the vehicle width direction extension member 1A. The front end is fastened and fixed to the pair of left and right mounting portions J1 on the cross member 5. Here, since the front and rear extension members 7 are joined to the pipe members 18 with their respective intermediate portions, the stiffness of the left and right pairs of front and rear extension members 7 itself can be changed from the beginning to the rigidity of the entire chassis member Ms. It's hardened enough. In the vicinity of the left and right ends of the pipe member 18, a pair of left and right clamping brackets 19 extending downward are respectively welded. As shown in Fig. 1, the pair of clamping brackets 19 on the left and right sides have a gum bush not showing the left and right boss portions 201 of the hollow bar member 20 installed in parallel under the pipe member 18. Through pins. The front end of the differential housing 16 is disposed below the central portion of the pipe member 18 and the hollow bar member 20, and protrudes into a pair of right and left connecting bosses 162 (only one side in FIG. 4A) above the front end. Formed. The connecting boss 162 overlaps the upper surface with the lower surface of the hollow bar member 20, and the longitudinal boss 22 penetrates through the connecting boss 162, and is mutually fastened by the bolt and the nut.

The rear suspension device S connects to the lower part of the vehicle body while allowing the rear wheels W, which are non-steering wheels, to be properly aligned while being allowed to move up and down, and includes a link mechanism s1 and an impact absorbing mechanism s2.

The link mechanism s1 has a knuckle 25 supporting the rear wheels W. The link mechanism s1 is provided on the vehicle body side by using four suspension arms to move the knuckle 25 side up and down, and to move up and down. Connect. That is, the lower arm 11 is rotatably pinned to the bent portion 103 of the knuckle 25 and the vehicle widthwise direction extending member 1A via a gum bush (not shown), and the upper arm 26 has a swing end. Toe control arm 27 is coupled to the knuckle 25 via an unillustrated ball joint, and the proximal end is pivotally coupled via a front and rear arm bracket of the front and rear extension member 7 and a gum bush not shown, respectively. Is pinably rotatably coupled to a knuckle 25 and a downward bracket 28 on the front and rear extending member 7 via a gum bush (not shown), and the trailing arm 29 is connected to the front end of the knuckle 25. The trailing arm brackets 30 of the side members 4 are rotatably pinned via a gum bush (not shown), respectively.

The shock absorbing mechanism s2 absorbs and reduces the reaction force fluctuation component from the road surface e input from the rear wheel W. The shock absorbing mechanism s2 includes the coil spring 31 and the shock absorber 32. The left and right coil springs 31 are mounted in a compression-pressed state between the spring receiving portion 101 formed in the bent cross member 1 and the lower spring receiving portion 111 of the lower arm 11. The left and right pairs of shock absorbers 32 have a lower end pin coupled to the lower end attachment portion 112 installed in the lower arm 11, and an upper end on the upper end attachment portion 34 provided on the side vertical wall plate 33 on the vehicle body side. It pins through this buffer member.

In the production of the vehicle body equipped with the chassis member Ms including the bent cross member 1 as described above, the chassis member Ms has a link mechanism s1, an impact absorbing mechanism s2, and a power transmission system PT. Some of the differential housings 16 and the like are prefabricated, and are supplied to the production line as a chassis member assembly. Subsequently, four fastening points of the chassis member Ms are provided to the lower wall structural members on which the attachment portions J1 and J2 are formed to face each other, and these opposite parts are fastened to each other by fastening bolts not shown.

In this case, the work of assembling the sub-assembly chassis member Ms on the production line is extremely simplified, the assembly work here can be easily performed, and the workability is improved. In addition, by assembling the components on the chassis member assembly side with respect to the chassis member Ms in advance, the assembling precision after the design can be easily secured.

In the vehicle body structure including the chassis member Ms described above, as illustrated in FIGS. 1 and 5, the spring receiving portion 101 and the bent portion 103 are vertically offset by the distance L. As shown in FIG. When the vehicle having such a vehicle body structure travels, when the left and right spring accommodating portion 101 receives an input load F, which is a large road surface reaction force, the inclined portion 102 having the spring accommodating portion 101 formed on the upper end side thereof. Is displaced and pressed to the vehicle body center side with the left and right side members 4 as the point of each bent part 103 side. However, in this case, the left and right edges of the reinforcing plate 8 are bonded to both inclined portions 102 formed with the spring receiving portion 101 on the upper end side, and the lower edge is bonded to the straight center portion 104 to fix the left and right slopes. Even when the part 102 side attempts to deform to the center of the vehicle body (indicated by the symbol M), both of the inclined portions in which the reinforcing plate 8 forms the reaction force R as the support member at the upper end side of the spring receiving portion 101 ( The function of applying to the side 102 can be exerted, and the deformation operation M to the vehicle body center side where both spring receiving portions 101 approach each other can be prevented reliably.

In particular, the vehicle body structure including the chassis member Ms of FIG. 1 is suitable for an off-road vehicle, has a long coil spring 31, sets a vertical displacement stroke of the rear wheel W relatively large, and has a spring accommodation portion 101. And the offset amount L in the vertical direction of the bent portion 103 are set relatively large, but both inclined portions 102 in which the reinforcing plate 8 here forms the spring receiving portion 101 on the upper side as a supporting member. The deformation operation M of) can be prevented reliably.

For this reason, the deformation | transformation to the vehicle body center side of the left and right inclination parts 102 which formed the spring accommodating part 101 in the upper end side is suppressed, the alignment state of the rear wheel W is maintained moderately, and steering stability is ensured, Durability can be prevented. In addition, the reinforcing plate 8 can reliably support the differential housing 16, can also maintain the function as a bracket of the differential housing 16, and attain the use of components.

In addition, since the rigidity of the bending cross member 1 is strengthened by welding and reinforcing the reinforcing plate 8, it is easy to adjust the resonance frequency toward the low frequency side when resonance of the chassis member Ms may occur. In addition, generation of load noise due to resonance can be reduced.

In addition, the chassis member Ms shown to FIG. 2, FIG. 5 joins and fixes the rear end of the front-back direction extension member 7 to both spring accommodating parts 101, and the left and right edges of the reinforcement board 8 are attached to the site | part. Bonding and fixing are performed, whereby the left and right ends of the reinforcing plate 8 exert a reaction force R on both the spring receiving portions 101 indirectly through the rear end of the front and rear extending member 7, and both spring receiving portions 101. ) Prevents the deformation operation (M) from approaching each other. On the other hand, the front-rear extension member 7 may be removed, and the left and right ends of the reinforcing plate 8 may be configured to directly apply the reaction force R to the vehicle body center side wall of both spring receiving portions 101, Also in this case, the effect similar to the chassis member Ms of FIG. 1 can be acquired.

In addition, the front-rear extension member 7 may be removed, and the main part of the rear suspension device S and the differential housing 16 may be attached to and supported by a chassis member (not shown) formed of a bent cross member. The case has almost the same effect as the chassis member Ms of FIG. 1, and the device is simplified.

In the above-described point, the lower body structure including the chassis member Ms has been described as supporting the rear suspension device S. Instead, the present invention has been described in the lower body structure supporting the front suspension device and the front differential housing instead. In this case, the same effects as those of the subframe structure of the vehicle in FIG. 1 can be obtained.

Although the above-described subframe structure is fastened and fixed to the attachment portions J1 and J2 on the side member side, a subframe structure (not shown) may be configured to be bonded and fixed to the side member side by welding or the like, in this case as well. The effect is almost the same as the subframe structure of the vehicle.

In the invention according to claim 1, the end edges of the reinforcing plate are fixed to the inclined portion formed with the spring receiving portion at the upper end side, so that the reinforcing plate is secured to the displacement in which both inclined portions having the spring receiving portion formed at the upper side as the supporting member approach each other. For this reason, the deformation | transformation to the vehicle body center side of the inclination part which provided the left and right spring accommodating part in the upper end side can be suppressed, the alignment state of a wheel can be maintained appropriately, operation stability can be prevented, and durability fall can be prevented. In addition, the reinforcing plate is intended to share the components that can reliably support the differential device of the vehicle. In addition, since the rigidity of the cross member is reinforced by the reinforcing plate, generation of rod noise due to the resonance vibration of the cross member can be reduced.

In the invention according to claim 2, the reinforcing plate is supported by both spring accommodating members as a supporting member by jointly fixing one end of the front and rear extension members to both spring receiving portions and joining and fixing one end of the reinforcing plate material to one end of the front and rear extension members. And it is possible to prevent the displacement of the inclined portions to approach each other, thereby maintaining the proper alignment of the wheel, to ensure the steering stability, to prevent the deterioration of durability, in particular, the front and rear extending member is the rigidity of the entire subframe It is possible to reinforce, and it is possible to reliably prevent the occurrence of misalignment in the alignment state of the wheel even from this.

Claims (2)

A pair of dish-shaped left and right spring receptacles 101 which are joined to and fixed to a pair of left and right side members extending in the front and rear directions of the vehicle and receive road surface reaction forces from the wheels via a coil spring; A pair of left and right inclined portions 102 extending downward from both spring receiving portions toward the center side of the vehicle body; A pair of left and right bent portions 103 formed at the lower ends of the inclined portions and connected with a suspension arm, A vehicle widthwise extending member 1A having a straight center portion 104 extending from both curved portions to a vehicle body center side; And a reinforcing plate member (8) having a vertical plate portion (801) to which the rear end of the differential device (16) of the vehicle is attached, An edge portion of the reinforcing plate member (8) is joined to and fixed to both of the inclined portions (102) and the straight center portion (104) of the vehicle width direction extending member (1A), respectively. According to claim 1, wherein the left and right pair of spring receiving portion 101 is fastened and coupled to the left and right pair of side members (4), one end is bonded to the center of the vehicle body from each spring receiving portion 101 and the other end is fixed Each side member 4 or a pair of left and right front and rear extension members 7 fastened to the cross member 1 which mutually couples the side members 4, A subframe structure, characterized in that the left and right edges of the reinforcing plate member (8) are bonded and fixed to one end of the front-rear extension member (7).